A Formation of Crystal Defects in Carbon‐Doped Czochralski‐Grown Silicon after a Three‐Step Internal Gettering Anneal

Abstract

which TMOS is partly substituted by modified alkoxysilanes containing nonhydrolyzable Si--C bonds. Coatings formed from the latter sol-gel systems show no crack formation, at least up to those temperatures at which the thermal decomposition of the included organic groups begins (system V: 473-523 K; system M: 523-573 K; system ME: 673-773 K; system P: 773-873 K).Thus the main conclusions which can be drawn from the results of this work are:The already known phenomenon of increasing the thermal stability of sol-gel films using a mixture of tetraalkoxysilanes and organically modified alkoxysilanes was confirmed in several cases (introduction of different organic groups into the sol-gel solution).Thermal stability of those organically modified sol-gel films strongly depends on the nature of the introduced organic groups, especially on the temperature of their decomposition. Thus crack formation occurs in the latter temperature range, if the organic groups are decomposed at temperatures lower than ca. 673 K. To obtain crack-free thick sol-gel films (up to 1400 nm were realized in planarization experiments), organic groups must be introduced the thermal decomposition of which occurs at temperatures higher than ca. 723 K.The organic components remarkably influence the structural evolution of the sol-gel film with increasing temperature. This is clearly documented by frequency changes of the asymmetric valence vibration band of the siloxane bridges.